(2x-1) 2=4x+9,
4x 2-4x+1-4x-9=0,
4x 2-8x-8=0,
4x 2-8x=8,
x 2-2x=2,
x 2-2x+1=3,
(x-1) 2=3,
x-1=±
3 ,
∴x 1=1+
3 ,x 2=1-
3 .